Wonder what HL3 will be, then, eh? Yeah, it's got multiplayer, but I'm not convinced it can rely upon old-school multiplayer styles anymore.

I doubt HL3 will be a standard 5-hour SP experience. It will likely be around 20 hours and have a fair amount of gameplay variety, as the previous games did (something that can't really be said of most shooters these days). If any shooter could get away with being completely linear and scripted, it would be HL3.

As much as I agree with your last line, I don't think Valve would ever be happy doing what they've always done (or what everyone else does.)